1. Field of the Invention
The present invention relates to a display device, and more particularly to a display device with improved operability.
2. Description of the Background Art
Today, image forming apparatuses including multi-functional peripherals are equipped with touch panel-type operation panels. Users can perform input operation to image forming apparatuses by touching keys displayed on the touch panels.
As a technique concerning touch panels, a technique for identifying a user whose operation is accepted is proposed. For example, Document 1 below discloses an information input apparatus including display means, input means provided on a display region of the display means, and body area network means using an upper surface of a protective layer of the input means as a touch panel surface for communication with an external device held by the operator through the operator's human body. According to the technique in Document 1 below, every time the information input apparatus accepts touch input operation, the user who performs the touch operation is identified thereby enabling a process allocated to an object.
Document 2 below discloses a print order apparatus in which a plurality of users can select their own images simultaneously and suitably with a single apparatus. When accepting a touch on a display portion of an image that each of a plurality of users wants to print, the print order apparatus detects the operation on the touch panel and identifies the user who performs the operation, using a user identifying sensor. Then, the image is specified to be printed as the user's print order.    Document 1: Japanese Patent Application Laid-Open No. 2010-286895    Document 2: Japanese Patent Application Laid-Open No. 2009-244725
However, the conventional display devices have a problem of poor operability. For example, in a case where a user A makes settings concerning print on an operation panel of a multi-functional peripheral, a submenu screen (pop-up screen) for accepting settings concerning print is displayed in a pop-up fashion on a screen displayed before then. When a user B different from the user A wishes to perform operation on the operation panel, for example, the following problem occurs.
Assume that the user A intends to make settings of print color, and the user B wants to select a document file for print. In general, the basic screen of the operation panel of a multi-functional peripheral presents keys including “color setting” and “paper setting” keys according to purposes. The user A presses the key “color setting” from among those keys. Upon accepting the press of the key, the operation panel displays a pop-up screen for “color setting” including “full-color,” “two-color,” or “black” setting keys on the basic screen. The user A makes color setting as desired by pressing the key of the item that the user A wants to set, for example, the “black key” on this pop-up screen. After completion of the color setting, the pop-up screen is closed. When the operation panel displays the pop-up screen for “color setting” as described above, the multi-functional peripheral gives operation authority over the pop-up screen only to the user A who makes the pop-up screen display. Therefore, the user B who does not have operation authority over the pop-up screen cannot operate the operation panel (that is, select a document file) until the pop-up screen is closed, and cannot execute the job until the operation by the user A is finished. The user B cannot help but stop the job halfway every time the user A displays a pop-up screen.
The similar problem as described above arises with Document 2. For example, when the user A changes the display screen of the print order apparatus from a screen displaying thumbnail images to a screen for print settings, the operation authority over the print setting screen is only given to the user A who makes the change to the screen for print settings, and another user B cannot resume the job until the display screen of the print order apparatus returns to the initial screen displaying thumbnail images. In these circumstances, in order to allow the user B to resume the job quickly, Document 2 proposes that print order information or information of shot images that have been input by the user B should be transferred to another neighboring print order apparatus. However, with this method, the user B still cannot resume the job if no print order apparatus exists nearby or if a neighboring print order apparatus is used by another user. In particular in a case where the display device is an operation panel of a multi-functional peripheral, a plurality of multi-functional peripherals are rarely arranged adjacent to each other in the same office.